As a method for producing a toner, there has been known a dissolution/suspension method of obtaining toner particles by mixing an oil phase containing a resin, a colorant, and an organic solvent, and an aqueous phase, and then removing the organic solvent from the mixture.
For example, the following five methods of obtaining toner particles have been proposed. A first method includes granulating a liquid having a polyester resin and a colorant dissolved or dispersed in a solvent, in an aqueous medium containing an inorganic dispersing agent, and then removing the solvent therefrom.
A second method includes mixing a binder resin and a colorant in an organic solvent, dispersing the resulting mixture in an aqueous medium containing a dispersion aid, removing the organic solvent from the resulting dispersion, and thereafter subjecting the dispersion to an acid-alkali treatment.
A third method includes mixing a coloring resin and a colorant in a solvent, dispersing the resulting composition in an aqueous medium in the presence of a hydrophilic inorganic dispersing agent, and removing the solvent from the resulting suspension.
A fourth method includes dissolving or dispersing a binder resin and a colorant in a solvent, dispersing the resulting composition mixing solution in an aqueous medium to prepare a suspension, adding a thickener in the resulting suspension, and thereafter removing the solvent from the suspension.
A fifth method includes dissolving and/or dispersing a binder resin and a colorant in an organic solvent having solubility to water to form an oil phase, mixing the oil phase and an aqueous phase with stirring to form a mixture, adding an emulsifier (neutralizing agent) thereto to form an emulsion, and removing the organic solvent from the emulsion.